Radiation-cured laminate label

ABSTRACT

Provided is a laminate label adapted for use on plastic containers suitable for containing a pharmaceutical or food grade product. The laminate label includes a substantially clear or translucent protective polymeric layer bound to a face stock by a radiation-cured adhesive composition formulated from a low-migration, radiation-curable adhesive composition containing at least 50% of one or more radiation-curable, carboxylic acid functional monomers.

FIELD OF THE INVENTION

The invention relates to a radiation-cured, laminate label. Theinvention also relates to the radiation-cured, laminate label bound to apolyolefin-based plastic container. The invention further relates to aradiation-cured, flexible laminate packaging material. The inventionalso relates to a radiation-curable adhesive composition suitable foruse in forming the laminate label and flexible laminate packagingmaterial.

BACKGROUND OF THE INVENTION

Label applications typically require the protection afforded by anoverlaminate of clear film, such as laminate labels which are subjectedto an excessive amount of abrasion or moisture. Specific examplesinclude labels for water, milk and other beverage grade containers, aswell as labels for food grade and pharmaceutical grade containers, thatare subjected to moist environments, such as condensation caused byrepeated trips into and out of refrigerators.

The laminate labels usually comprise an outer clear protective filmbound to a face stock using a radiation-cured laminating adhesive. Theprotective film is usually formed from a polyolefin, such aspolypropylene, but can also be formed from other suitable polymericmaterials, such as polystyrenes or polyesters. A pressure sensitiveadhesive is usually applied to the back of the face stock for bondingthe laminate label to a container.

It has recently been found that when the radiation-curable laminatingadhesive is applied to the face stock, radiation-curable monomers adsorbinto the face stock. The face stock hinders or prevents curing of themonomers adsorbed therein and thus, the adsorbed monomers are not bound.Over time, these unbound monomers can undesirably migrate through theface stock, pressure sensitive adhesive layer, and through thepolyolefin container to contaminate the contents of the container. Thisproblem is especially prevalent in extended shelf life items, such asbeverage and pharmaceutical containers. The radiation-curable monomerscan cause an undesirable odor and/or taste in the container contents.

There is a need for a radiation-cured, laminate label which does notleach monomers into the contents of polyolefin containers.

A similar problem also exists in flexible laminate packaging materialswhich contain a polyolefin layer and use a radiation-curable adhesive tobond the layers together. Uncured radiation-curable monomers can migratethrough the polyolefin layer in the same manner as polyolefin containersand undesirably contaminate the contents thereof. Thus, there is a needfor a radiation-cured, flexible laminate packaging material which doesnot leach monomers into the contents thereof.

SUMMARY OF THE INVENTION

An objective of the invention is to provide a radiation-cured, laminatelabel which does not leach radiation-curable monomers into the contentsof polyolefin containers.

Another objective of the invention is to provide a radiation-cured,flexible laminate packaging material which does not leachradiation-curable monomers into the contents thereof.

The above objectives and other objectives are surprisingly obtained byusing a low-migration, radiation-curable adhesive composition formulatedfrom carboxylic acid functional monomers.

The invention provides a novel laminate label adapted for use on plasticcontainers suitable for containing a pharmaceutical or food gradeproduct. The laminate label comprises a substantially clear ortranslucent protective polymeric layer bound to a face stock by aradiation-cured adhesive composition formulated from a low-migration,radiation-curable adhesive composition comprising at least 50% of one ormore radiation-curable, carboxylic acid functional monomers.

The invention also provides a novel labeled plastic container suitablefor containing a pharmaceutical or food grade product comprising:

a walled structure comprising a polyolefin material defining an interiorspace suitable for containing a liquid or solid food product orpharmaceutical product; and

a laminate label bound to an outer surface of said walled structure.

The laminate label comprises a substantially clear or translucentprotective polymeric film bound to a face stock by a radiation-curedcomposition formulated from a low-migration, radiation-curable adhesivecomposition comprising at least 50% of one or more radiation-curable,carboxylic acid functional monomers.

The invention further provides a novel laminated flexible packagingmaterial suitable for containing a pharmaceutical or food grade productcomprising:

a polyolefin film defining an interior space suitable for containing aliquid or solid food product or pharmaceutical product; and

at least one other film bound to the polyolefin film by aradiation-cured adhesive composition formulated from a radiation-curablecomposition comprising at least 50% of one or more radiation-curable,carboxylic acid functional monomers.

The invention also provides a novel low-migration, radiation-curableadhesive composition comprising at least 50% of one or moreradiation-curable, carboxylic acid functional monomers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side, cross-sectional view of an improved laminatelabel according to the present invention;

FIG. 2 illustrates a side, cross-sectional view of a polyolefincontainer suitable for containing a pharmaceutical or food producthaving the improved laminate label bonded on an outer surface thereof;and

FIG. 3 illustrates a side, cross-sectional view of a radiation-cured,flexible laminate packaging material.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Low-migration,Radiation-curable Adhesive Composition

The low-migration, radiation-curable adhesive composition (hereinafterreferred to as “radiation-curable adhesive composition”) comprises atleast 50 wt. % of one or more carboxylic acid functional,radiation-curable monomers (hereinafter referred to as “carboxylic acidfunctional monomer”). Preferably, the radiation-curable adhesivecomposition comprises at least 80 wt. % of one or more carboxylic acidfunctional monomers, and more preferably at least 90 wt. % of one ormore carboxylic acid functional monomers. All wt. % are based on thetotal weight of the radiation-curable composition unless statedotherwise herein. While the radiation-curable composition may containconventional non-carboxylic acid functional monomers if desired,preferably substantially all of the radiation-curable monomers presentin the radiation-curable adhesive comprise at least one carboxylic acidfunctional group.

The carboxylic acid functional monomer preferably has a number averagemolecular weight of from about 100 to about 3000, more preferably fromabout 150 to about 2000, and most preferably from about 200 to about1500. The simplest type of carboxylic acid functional monomer is acrylicacid. However, acrylic acid is not desirable because of odor, toxicityand low molecular weight. Therefore, preferred radiation-curableadhesive compositions are substantially free of acrylic acid.

One skilled in the art will easily be able to form the desiredcarboxylic acid functional monomer based on well known reactionmechanisms. For example, using the well known reaction between ahydroxyl functional group and an anhydride, a compound containing both ahydroxyl functional group and a desired radiation-curable functionalgroup can be reacted with an anhydride compound to form the desiredcarboxylic functional monomer. Suitable anhydrides include, but are notlimited to:

phthalic anhydride;

isophthalic anhydride;

terephthalic anhydride;

trimellitic anhydride;

tetrahydrophthalic anhydride;

hexahydrophthalic anhyride;

tetrachlorophthalic anhydride;

adipic anhydride;

azelaic anhydride;

sebacic anhydride;

succinic anhydride;

glutaric anhydride;

malonic anhydride;

pimelic anhydride;

suberic anhydride;

2,2-dimethylsuccinic anhydride;

3,3-dimethylglutaric anhydride;

2,2-dimethylglutaric anhydride;

dodecenylsuccinic anhydride;

nadic methyl anhydride;

HET anhydride; and the like.

The compound containing a hydroxyl functional group and aradiation-curable functional group (“hydroxy functional,radiation-curable compound”) can contain any desired radiation-curablefunctional group suitable for the desired application. Theradiation-curable functional group preferably comprises ethylenicunsaturation. Examples of suitable ethylenic unsaturation includeacrylate, methacrylate, styrene, vinylether, vinyl ester, N-substitutedacrylamide, N-vinyl amide, maleate esters or fumarate esters.Preferably, the ethylenic unsaturation is provided by a group containingacrylate or methacrylate. Use of the term “(meth)acrylate” refers toeither acrylate or methacrylate, or mixtures thereof.

Examples of suitable hydroxy functional, radiation-curable compoundscontaining (meth)acrylate groups include the following, but are notlimited thereto:

2-hydroxyethyl (meth)acrylate;

2-hydroxypropyl (meth)acrylate;

2-hydroxybutyl (meth)acrylate;

2-hydroxy 3-phenyloxypropyl (meth)acrylate;

1,4-butanediol mono(meth)acrylate;

4-hydroxycyclohexyl (meth)acrylate;

1,6-hexanediol mono(meth)acrylate;

neopentylglycol mono(meth)acrylate;

trimethylolpropane di(meth)acrylate;

trimethylolethane di(meth)acrylate;

pentaerythritol tri(meth)acrylate;

dipentaerythritol penta(meth)acrylate; and

hydroxy functional (meth)acrylates represented by the following formula,

wherein R₁ is a hydrogen atom or a methyl group and n is an integer from1 to 5. Commercially available example include the hydroxy terminated(meth)acrylate prepolymers sold as “Tone” prepolymers (Union Carbide).The (meth)acrylate compounds can be used either alone or in admixture oftwo or more of them. Among these (meth)acrylate compounds,2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate areespecially preferred. Examples of hydroxy functional, radiation-curablecompounds having vinyl ether functional groups include, for example,4-hydroxybutyl vinyl ether, and triethylene glycol monovinyl ether.

Preferably, the radiation-curable functional group is acrylate ormethacrylate, with acrylate being the most preferred.

A particularly preferred carboxylic acid functional monomer is theproduct of the reaction of 2-hydroxyethylacrylate with succinicanhydride, as shown in the following formula:

If desired, the carboxylic acid functional monomer can also be formed byreacting a suitable dicarboxylic acid functional compound with a hydroxyfunctional, radiation-curable compound. However, this method is notpreferred since water is formed during the reaction of the hydroxylgroup with a carboxylic acid group, which water must be removed prior touse of the carboxylic monomer in the radiation-curable adhesivecomposition.

Carboxylic acid functional monomers can also be formed by variouscombinations of polyanhydrides and/or polyols, as desired.

While not preferred, oligomeric forms of acrylic acid can also be usedas the caboxylic acid functional monomer, which can be formed, forexample, by dimerizing or trimerizing acrylic acid by well known selfaddition reactions. A stable dimer compound is betacarboxyethylacrylate(“BCEA”). However, BCEA is not preferred since it usually containsresidual amounts of acrylic acid.

One skilled the art will easily be able to formulate theradiation-curable adhesive composition to provide a suitable viscosityfor the desired application. Usually, the viscosity of theradiation-curable adhesive composition should be low, for example about3000 centipoise or less, at the application temperature, to facilitateapplication to the face stock. Usually, the application temperature isroom temperature (25° C.). However, higher application temperatures canbe utilized as desired. The carboxylic acid functional monomerpreferably has a low viscosity, in order to avoid the use of diluentmonomers, to provide a viscosity that is suitable for application of theradiation-curable adhesive to the face stock. Suitable viscosities ofthe carboxylic functional monomer include from about 100 to about 2000centipoise at the application temperature, more preferably from about200 to about 700 centipoise at the application temperature.

When the radiation-curable adhesive is formulated for curing by exposureto visible light, ultraviolet light, or the like, one or morephotoinitiators and/or photosensitizers can be used as polymerizationinitiators to enhance the cure speed. Examples of suitablephotoinitiators and photosensitizers include:

2,2′-(2,5-thiophenediyl)bis(5-tert-butybenzoxazole);

1-hydroxycyclohexyl phenyl ketone;

2,2-dimethoxy-2-phenylacetophenone;

xanthone;

fluorenone;

anthraquinone;

3-methylacetophenone;

4-chlorobenzophenone;

4,4′-dimethoxybenzophenone;

4,4′-diaminobenzophenone;

Michler's ketone;

benzophenone;

benzoin propyl ether;

benzoin ethyl ether;

benzyl dimethyl ketal,1-(4-isopropylphenyl)-2hydroxy-2-methylpropane-1-one;

2-hydroxy-2-methyl-1phenylpropane-1-one;

methylbenzoyl formate

thioxanthone;

diethylthioxanthone;

2-isopropylthioxanthone;

2-chlorothioxanthone;

2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropane-1-one; and

2,4,6-trimethylbenzoyldiphenylphosphine oxide.

Commercially available examples include IRGACURE 184, 369, 500, 651,819, 907, and 2959, and Darocur 1173 (Ciba Geigy); Lucirin TPO (BASF);and Ebecryl P36 and P37 (UCB Co.).

Preferably, polymeric photoinitiators are utilized in theradiation-curable adhesive composition. The use of polymericphotoinitiators further reduces the possibility of photoinitiator orfragments of the photoinitiator migrating. Examples of suitablepolymeric photoinitiators include, but are not limited to, thecommercially available KIP 100 and KIP 150 (Lamberti).

If desired, one or more photoinitiators and/or photosensitizers can beincorporated in the radiation-curable adhesive coating composition in anamount of about 0.1 to about 10% by weight of the total composition.

If the radiation-curable adhesive composition is formulated to utilize afree-radical curing system by exposure to an electron beam, aphotoinitiator is generally not beneficial. However, in cationicallycured systems, a photoinitiator is beneficial even when performing anelectron beam cure. Based on the disclosure provided herein, one skilledin the art of formulating radiation-curable adhesive compositions willeasily be able formulate a suitable curing system for the desiredapplication, without undue experimentation.

The radiation-curable adhesive can also include additives such asfillers, flow additives, anti-foaming additives, pigments, dyes, orresinous materials dispersed or solubilized in the composition. Theselection and use of such additives is within the skill of the art.

The carboxylic acid functional monomers used in the present inventionhave been found to provide the unexpected combination of sufficientadhesion to low surface energy layers, such as polyolefin protectivefilms, to avoid delamination and substantially avoid migrating throughpolyolefin containers in the uncured free monomer form.

The radiation-curable adhesive composition can be used to form improvedlaminate labels, as described below. The radiation-curable adhesivecomposition can also be used to form improved flexible laminatepackaging materials, as described below.

Laminate Label and Polyolefin Container Having Laminate Label

The present invention will now be described with reference to theattached drawings. As shown in FIG. 1, the laminate label 1 includes asubstantially clear or translucent protective polymer layer 2, which isbound to a face stock 6 using the radiation-curable adhesive compositiondescribed herein 4. An optional pressure sensitive adhesive layer 8 isshown on the back of the face stock 6 opposing the protective polymerlayer 2. The laminate label can also include other layers as desired andcommonly used in the art, such as a release liner 9. The release liner 9should be removed from the label 1 prior to application. The face stockcan include printed material formed by well known methods. FIG. 2illustrates the laminate label 1 bonded to a polyolefin container 10 bythe pressure sensitive adhesive 8.

It has been found that radiation-curable monomers usually adsorb intothe face stock 6 when applied thereon. The face stock 6 hinders orprevents curing of the monomers adsorbed therein and thus, the adsorbedmonomers are not bound in the formed laminate label. Over time, theseunbound monomers can migrate through the face stock 6 and pressuresensitive adhesive 8 to reach the polyolefin container 10. The monomershave also been found to undesirably migrate through the polyolefincontainer 10 and contaminate the contents thereof. The monomers cancause an undesirable odor and/or taste in the container contents.

The radiation-curable adhesive composition according to the presentinvention, is formulated form low-migration, carboxylic acid monomers.It has been found that the carboxylic acid monomers migrate throughpolyolefin containers in significantly less amounts than conventionallyused monomers in conventional laminate labels.

It has also been found that the carboxylic acid monomers used in thepresent invention provide the unexpected combination of providingsufficient adhesion to low surface energy layers when suitably cured,such as polyolefin protective films, to avoid delamination and theysubstantially avoid migrating through the walls of polyolefin container10 when in the free uncured monomer form.

The substantially clear protective polymeric layer 2 can be formed fromany suitable polymeric material. Examples of suitable polymericmaterials include polyolefins, polyesters and polystyrenes. Preferably,the protective polymeric layer is formed from a polyolefin. Examples ofsuitable polyolefins include, but are not limited to, homopolymers ofcopolymers of ethylene, butylene, propylene, hexene, octene, etc.Preferred polyolefins include polypropylene and polyethylene, such ashigh-density polyethylene (HDPE) or linear-low-density polyethylene(LLDPE), polyiosbutylene (PIB). Polypropylene is especially preferred.Oriented forms of polypropylene can be used as desired, such asbiaxially oriented (BOPP) or oriented polypropylene (OPP). When usingultra-violet (UV) light to cure the radiation-curable adhesivecomposition, a polymeric material should be selected which does notprevent or substantially inhibit curing of the radiation-curableadhesive by absorbing or shielding the UV light. However, when electronbeam curing is used, the polymeric material selected can besubstantially more opaque than when UV curing. The protective polymericlayer 2 is usually abut 0.2 to about 2 mils thick, preferably about 0.4to about 1.5 mils.

Face stocks are well known in the label art. The face stock usuallycontains printed material in form of ink and/or from electrophotographictechniques. Any suitable face stock can be utilized in the presentinvention. While bleached kraft paper is the most often used face stockmaterial for labels, the face stock can be formed from syntheticpolymeric materials, such as polyolefins, polyesters andpolyvinylchlorides, if desired. The face stock can also be formed fromcombinations of synthetic and plant fibers, in woven or non-woven forms.The present invention is especially useful for face stocks which arecapable of adsorbing radiation-curable monomers, such as fibrousmaterials formed from synthetic and/or plant fibers, or porous polymericfilms. Suitable face stocks are disclosed in U.S. Pat. Nos. 5,284,688and 5,830,571, which are incorporated herein by reference.

Once the printed material is formed on the face stock, the protectivepolymeric layer and radiation-curable adhesive composition can beapplied to the face stock using well known techniques. A preferredmethod includes use of a flexographic printing press to print the facestock and apply the radiation-curable adhesive in line. Theradiation-curable adhesive composition can be cured by well knownmethods, such as by UV light from medium pressure mercury lamps or lowintensity fluorescent lamps directly through the protective polymericlayer. Alternatively, electron beam radiation may be used to cure theradiation-curable adhesive composition. The laminate label can be formedusing the UV curing methods described in U.S. Pat. Nos. 5,262,216 and5,284,688, if desired.

Pressure sensitive adhesives are now well known in the label art. Anysuitable pressure sensitive adhesive can used on the laminate labelaccording to the present invention. U.S. Pat. Nos. 5,202,361; 5,262,216;5,284,688; 5,385,772; 5,874,143, disclose examples of suitable pressuresensitive adhesives that can utilized in the laminate label. Thepressure sensitive adhesive can be applied to the laminate label usingwell known techniques, such as shown in U.S. Pat. No. 5,861,201, thecomplete disclosure of which is incorporated herein by reference.

Examples of suitable polyolefin containers include, but are not limitedto, beverage or water containers, pharmaceutical containers, and foodcontainers. Intravenous bags, polyolefin wraps, and bottles are alsoexamples suitable polyolefin containers. The polyolefin container can beformed from any of the polyolefin materials described herein.

Flexible Laminate Packaging Material

Multilayer packages may be formed by co-extrusion or by using anadhesive to bond the layers together. When printed material is insertedbetween layers, usually the layers cannot be formed by co-extrusion andan adhesive, such as a radiation-curable adhesive, must be used to thebond the layers together. Other considerations for using aradiation-curable adhesive instead of co-extrusion include high speedprocessing, energy savings, and equipment reductions. Theradiation-curable, adhesive composition described herein is suitable foruse in forming radiation-cured, flexible laminate packaging materials(hereinafter “flexible laminate packaging materials”).

As shown in FIG. 3, the flexible laminate packaging material 20 includesat least one first layer 22 laminated to a polyolefin layer 26 by aradiation-cured, adhesive 24. The flexible laminate packaging material20 can also include other layers as desired. Examples of suitablematerials for the first layer 22 and other optional layers include, butare not limited to, paper, metalized films, co-extruded films, polyesterfilms, and white polypropylene films.

The low-migration, radiation-curable adhesive composition describedherein can be used to provide an improved flexible laminate packagingmaterial in which the problem of contamination from migrating monomersis substantially reduced. The radiation-curable, adhesive compositiondescribed herein can be cured in the same manner as described above inreference to the laminate label.

At least one of the first layer 22 or the polyolefin layer 26 ispreferably substantially clear to facilitate UV curing. Suitablesubstantially clear films can be formed from materials similar to thosedescribed in reference to the protective layer 2 described herein. Thepolyolefin layer 26 can be formed from any of the polyolefin materialsdescribed herein. U.S. Pat. No. 5,399,396 discloses examples of suitablelayers for use in flexible, laminate packaging material, which areincorporated herein by reference. Neither the first layer 22 or thepolyolefin layer 26 need to be substantially clear if EB curing is to beused. If desire, the clear layer can be the innermost layer for printedmaterial readable from the inside surface of bag.

Another example of flexible laminate packaging material includes anoutside clear layer which has been reverse printed on inside surfacethereof bonded to a clear polyolefin using the radiation-curable,adhesive composition. A further example of a flexible laminate packagingmaterial includes a clear layer bonded to a white polyolefin layerhaving printed material on an outside surface thereof bonded togetherusing the radiation-curable, adhesive composition.

The improved flexible laminate packaging material can be used to containbeverages, pharmaceuticals, medical and dental devices, and foodproducts. Preferred examples are snack food packaging and fruit juicecontainers.

The invention will now be further described with reference to thefollowing non-limiting Examples and Comparative Examples.

EXAMPLE 1

An improved radiation-curable, adhesive composition was formulated asfollows:

92.85 wt. % 1,2-Ethanedicarboxylic acid Mono [2-[(1 oxo-2-propehyl)oxy]Ethyl Ester;

5.0 wt. % 1,2-Benzenedicarboxylic acid Mono [2-[(1 oxo-2-propehyl)oxy]Ethyl Ester;

0.1 wt. % Fluoroalkylpolyester;

2.0 wt. % Oligo[2-hydroxy-2-methyl-1-[4(1-methylvinyl)phenyl]propanone]; and

0.05 wt. % 2,2′-(2,5-thiophenediyl)bis[5-tert-butylbenzoxazole].

All wt. % are based on the total weight of the radiation-curablecomposition.

Laminate labels were formed using a flexographic printing press runningat speeds up to 300 ft/min. A 300 line/inch anilox roll was used toapply the radiation-curable laminating adhesive to one surface of apressure sensitive label stock, Fasson 55 pound face paper, which wascoated on the opposing surface with DL50 adhesive. Clear 0.5 mil coronatreated OPP film was nipped to the wet radiation-curable laminatingadhesive. The radiation-curable adhesive was cured by exposure to UVlight from a 400 w/in. medium pressure mercury arc lamp. The labels weredye cut in line to a size appropriate to labeling one-gallon highdensity polyethlyene (HDPE) containers of drinking water.

Four labels were bonded on a one-gallon HDPE container of drinkingwater. The labeled container was stored at 130° F. for 20 days. Thewater was then analyzed by gas chromatography and mass spectroscopy(GC-MS) upon desorption from a C18 column. The analysis has a detectionlimit has about 1 part per billion. No components from theradiation-curable adhesive were detected in the water under thesecondition.

EXAMPLE 2

2.08 grams of the uncured low-migration, radiation-curable adhesivecomposition according to Example 1 was spread directly onto the pressuresensitive adhesive of three labels. This was about 250 times moreuncured radiation-curable adhesive compared to normal labels. The labelswere applied to a one-gallon HDPE container of water and aged at 130° F.for 10 days. The analysis detected only 11 parts per billion of acrylatemonomer in the water in spite of the unusually high loading of uncuredadhesive.

COMPARATIVE EXAMPLE A

A commercially available radiation-curable adhesive compositioncontaining 1,6-hexanediol diacrylate monomer (12000LA from NorthwestCoatings Corp.) was used to prepare labels by the same method asdescribed in Example 1. Three labels were applied to one-gallon HDPEcontainer of water and then aged at 130° F. for 10 days. The water wastested in the same manner as in Example 1. 1,6 hexanediol diacrylate wasdetected in the water at a level of 102 parts per billion.

COMPARATIVE EXAMPLE B

A commercially available radiation-curable adhesive containingdipropylene glycol diacrylate monomer (15135LA from Northwest CoatingsCorp.) was used to prepare labels by the same method as described inExample 1. Three labels were applied to one-gallon HDPE container ofwater and then aged at 130° F. for 10 days. The water was tested in thesame manner as in Example 1. Dipropylene glycol diacrylate monomer wasdetected in the water at a level of 9 parts per billion.

The test results demonstrate that the improved radiation-curableadhesive composition is capable of providing a laminate label whichsubstantially reduces the risk of contaminating the contents of apolyolefin container with uncured monomer.

While the claimed invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to one ofordinary skill in the art that various changes and modifications can bemade to the claimed invention without departing from the spirit andscope thereof.

What is claimed is:
 1. A laminate label suitable for use on polyolefincontainers suitable for containing a pharmaceutical or food gradeproduct, said laminate label comprising: a substantially clear ortranslucent protective polymeric layer bound to a face stock by aradiation-cured adhesive composition formulated from a low-migration,radiation-curable adhesive composition comprising at least 50% of one ormore radiation-curable, carboxylic acid functional monomers, whereinsaid face stock comprises at least one selected from the groupconsisting of paper, synthetic material that absorbes radiation-curablemonomers and inhibiting radiation-curing of the adsorbedradiation-curable monomers, and combinations thereof, and wherein saidlaminate label has been formed by ultraviolet light curing of saidlow-migration, radiation-curable adhesive composition through saidsubstantially clear polymeric film.
 2. A laminate label according toclaim 1, wherein said laminate label has been formed by electron beamcuring of said low-migration, radiation-curable adhesive compositionthrough said substantially clear polymeric film.
 3. A laminate labelaccording to claim 1, wherein said laminate label contains a pressuresensitive adhesive on a back surface thereof.
 4. A laminate labelaccording to claim 1, wherein said low-migration, radiation-curableadhesive composition comprises at least 80% of said one or moreradiation-curable, carboxylic acid functional monomers.
 5. A laminatelabel according to claim 1, wherein said low-migration,radiation-curable adhesive composition comprises at least 90% of saidone or more radiation-curable, carboxylic acid functional monomers.
 6. Alaminate label according to claim 1, wherein said low-migration,radiation-curable adhesive composition is substantially free ofnon-carboxylic acid functional monomers.
 7. A laminate label accordingto claim 1, wherein said radiation-curable, carboxylic acid functionalmonomer comprises an acrylate functional group.
 8. A laminate labelaccording to claim 1, wherein said radiation-curable, carboxylic acidfunctional monomer comprises a methacrylate functional group.
 9. Alaminate label according to claim 1, wherein said radiation-curable,carboxylic acid functional monomer comprises the half ester of a hydroxy(meth)acrylate compound and an anhydride.
 10. A laminate label accordingto claim 9, wherein said anhydride is selected from the group consistingof phthalic anhydride; isophthalic anhydride; terephthalic anhydride;trimellitic anhydride; tetrahydrophthalic anhydride; hexahydrophthalicanhydride; tetrachlorophthalic anhydride; adipic anhydride; azelaicanhydride; sebacic anhydride; succinic anhydride; glutaric anhydride;malonic anhydride; pimelic anhydride; suberic anhydride;2,2-dimethylsuccinic anhydride; 3,3-dimethylglutaric anhydride;2,2-dimethylglutaric anhydride; dodecenylsuccinic anhydride; nadicmethyl anhydride; and HET anhydride and said hydroxy (meth)acrylatecompound is selected from the group consisting of 2-hydroxyethyl(meth)acrylate; 2-hydroxypropyl (meth)acrylate; 2-hydroxybutyl(meth)acrylate; 2-hydroxy 3-phenyloxypropyl (meth)acrylate;1,4-butanediol mono(meth)acrylate; 4-hydroxycyclohexyl (meth)acrylate;1,6-hexanediol mono(meth)acrylate; neopentylglycol mono(meth)acrylate;trimethylolpropane di(meth)acrylate; trimethylolethane di(meth)acrylate;pentaerythritol tri(meth)acrylate; dipentaerythritolpenta(meth)acrylate; and hydroxy functional (meth)acrylates representedby the following formula,

wherein R₁ is a hydrogen atom or a methyl group and n is an integer from1 to
 5. 11. A laminate label according to claim 9, wherein saidanhydride comprises at least one of succinic anhydride or phthalicanhydride and said hydroxy (meth)acrylate comprises2-hydroxyethylacrylate.
 12. A laminate label according to claim 1,wherein said carboxylic acid monomer has a number average molecularweight of from about 100 to about
 3000. 13. A laminate label accordingto claim 1, wherein said carboxylic acid monomer has a number averagemolecular weight of from about 150 to about
 2000. 14. A laminate labelaccording to claim 1, wherein said carboxylic acid monomer has a numberaverage molecular weight of from about 200 to about
 1500. 15. A laminatelabel according to claim 1, wherein said protective polymeric layercomprises at least one polymeric material selected from the groupconsisting of polyolefins, polyesters and polystyrenes.
 16. A laminatelabel according to claim 1, wherein said protective polymeric layercomprises a polyolefin.
 17. A laminate label according to claim 16,wherein said polyolefin comprises at least one selected from the groupconsisting of homopolymers or copolymers of ethylene, butylene,propylene, hexene, and octene.
 18. A laminate label according to claim16, wherein said polyolefin comprises polypropylene.
 19. A laminatelabel according to claim 1, wherein said low-migration,radiation-curable adhesive composition contains a polymericphotoinitiator.
 20. A laminate label according to claim 1, wherein saidprotective polymeric layer has a thickness of from about 0.2 mils toabout 2 mils.
 21. A laminate label according to claim 1, wherein saidprotective polymeric layer has a thickness of from about 0.4 mils toabout 1.5 mils.
 22. A laminate label according to claim 1, wherein saidradiation-cured adhesive composition is free of acrylic acid.
 23. Alaminate label according to claim 1, wherein said radiation-curedadhesive composition is free of monomers which leach through apolyethylene layer at greater than 11 parts per billion when the labelis applied to a one gallon polyethylene container at 130° F. for 10days.
 24. A laminate label according to claim 1, wherein said face stockcontains printed material.
 25. A laminate label according to claim 1,wherein said radiation-curable carboxylic acid functional monomers havea viscosity of about 100 to about 2000 centipoise at 25° C.
 26. Alaminate label according to claim 1, wherein said protective polymericlayer comprises a coextruded film containing a polyolefin.